FAIRFAX, Virginia (CNN) --A Maryland prison guard testified Thursday that teenage sniper suspect Lee Boyd Malvo told him he shot other people who were not listed among the 10 victims of the sniper shootings in the Washington metropolitan area, and said if he got out, he would do it again.

Corp. Wayne Davis, a guard at Baltimore, Maryland's so-called Supermax prison facility, said he talked to Malvo shortly after his arrest last October. He said the young man claimed to have shot a senator on a golf course, a little black girl, a man who used to pick on him and the driver of a Brinks' truck.

"When he talked about all the shootings, I was under the impression that he was exaggerating to me," Davis testified.

Malvo also cited different reasons for the shootings, which he is alleged to have committed with John Allen Muhammad.

Davis testified that Malvo told him they committed the shootings because white people shot (Nation of Islam leader) Louis Farrakhan, and that when Farrakhan was in the hospital, the hospital gave him cancer.

When Davis asked him why he also then shot black people, he said Malvo told him that if he only shot white people, the police would have caught up with him more quickly.

"I told him, 'You're crazy.' He said if he got out, he'd do the same thing all over again," Davis testified.

Another guard at the same facility, Capt. Joseph Stracke, also testified Thursday that Malvo said the pair chose Montgomery County for the beginning of their shooting spree in the Washington metropolitan area "because that's where the rich people are."

He said Malvo also told him the shootings were part of a plan to get money from the government and said "they were going to withdraw $100,000 or $200,000" at a time from a bank machine.

When asked another time why he committed the shootings, Stracke said Malvo replied that there were lots of ghettos in America and he was trying to clean them up.

The guards' testimony came during a hearing at which defense attorneys sought to prevent Malvo's statements to jailers from being used at his trial.

Circuit Court Judge Jane Marum Roush took the motion under advisement and said she would rule on the matter August 29.

Stracke said Malvo also talked about the shooting of 13-year-old Iran Brown, saying that he shot the boy because he wanted to upset then-Montgomery County Police Chief Charles Moose. (Full story)

Malvo claimed his plan to upset the chief worked, noting that Moose cried at a news conference discussing the October 7 shooting of the junior high student, Stracke said.

'Shoot a bus full of kids'

Charles Moose was chief of Montgomery County police in the fall of 2002.

Brown was also shot, Malvo reportedly said, because police weren't responding to the snipers' request for money.

Malvo "said he planned to shoot a whole bus full of kids," Stracke said.

The plan failed, Malvo reportedly said, because the bus pulled into the school parking lot the wrong way that day in Bowie, Maryland.

Stracke also said that on another occasion, Malvo claimed to have trained his rifle's scope on a policeman's head while the policeman talked to Malvo's alleged accomplice, Muhammad, and intended to shoot the officer when anything went wrong. He was not specific as to when this occurred.

At another shooting, Davis testified, Malvo told him he broke down his rifle, put it in a knapsack and walked right by police who had responded to the scene. It was not clear which shooting incident this was.

And in Baltimore, Malvo said there was a plan to shoot a pregnant woman, but Muhammad called off the shooting because a police helicopter was hovering overhead, Stracke testified.

Malvo kept lips zipped at first

Malvo was arrested in the early morning hours of October 24 and was taken to Montgomery County Police Family Services' Division office near Gaithersburg, Maryland. There he refused to speak to a police detective, gesturing as if zippering his mouth closed. During the next several hours, however, he communicated with detectives using hand gestures, pantomime and pretending to write on a desk.

Defense attorneys Thursday argued that the interrogation was illegal, ambiguous and should not be admitted as evidence.

Prosecutors claimed the interrogation was legal, but acknowledged it was ambiguous and said they do not intend to use it.

Later on October 24, Malvo was taken to the Maryland Correctional Center in Baltimore, which is known as "Supermax," and was placed in an area known as "the cadre" -- a unit for violent and suicidal inmates. He also maintained his silence there.

"For three days, he was giving me the thumbs up," when asked how he was doing, Stracke said. On Saturday October 26, Malvo knocked on his cell door and pointed at one of the guards' plate of fish. "I said 'if you want something you have to ask for it.'"

"He then asked verbally for the fish," and the other guard, Davis, gave it to him.

Malvo told the guards that he wouldn't eat before going on "a mission." Asked what he meant, Malvo said "go out killing people."

He said he would not eat, because the fasting would result in "more oxygen to the brain."

Malvo is charged with the October 14 shooting of FBI analyst Linda Franklin. Muhammad faces trial in Prince William County, Virginia, for the October 9, 2002, shooting of Dean Harold Meyers in Manassas, Virginia.

Together, 18-year-old Malvo and Muhammad, 42, have been charged with 10 killings in the Washington, D.C. area last fall, and have been linked to slayings in Louisiana, Alabama, Georgia and Washington state in what prosecutors have said was a scheme to extort $10 million from the government.

Malvo is scheduled to stand trial in November. If convicted of capital murder, Malvo could face the death penalty.